The present invention relates to a drug for treating a patient with ulcerative colitis, which is one of the intractable diseases of unknown origin, a method for screening such a drug, a method for treating a patient with the disease, a prophylactic drug, a method for preventing such a disease, a vaccine for the disease, a diagnostic drug, a diagnostic method, an experimental model for the disease and an experimental animal for the disease.
Ulcerative colitis is one of the intractable diseases of digestive tracts and a unknown etiology. It has conventionally been regarded as an advantageous opinion that the ulcerative colitis would be a kind of autoimmune disease. For this reason, there have been used, for instance, steroid hormones, salazosulfapyridine and 5-aminosalicylic acid (5-ASA) having an anti-inflammatory action. The administration of these drugs may clinically improve the symptoms of patients with this disease, but the disease recurs in most of cases, on a long term follow-up. Moreover, inflammatory findings still remain in both endoscopic and pathological findings in most of the cases of the disease, although the symptoms are improved. In other words, there has not yet been any drug for completely curing the disease.